Magnetic assembly



NOV- 13, 1956 A. w.'AH| GR|-:N 2,770,759

MAGNETIC ASSEMBLY Filed Feb, 8, 1955 T lo IN VEN TOR. xe? M /bigrea BY MM( w'uwwg,

ATTORNEYS United States Patent Office 2,770,759 Patented Nov. 13, 1956 MAGNETIC ASSEMBLY Axel W. Ahlgren, Rockford, Ill., assignor to Amerock Corporation, a corporation of Illinois Application February 8, 1955, Serial No. 486,776

4 Claims. (Cl. 317-159) mit the magnet and pole pieces to be inserted and the housing is closed by a nonmagnetic backing plate which holds the parts in place during shipping and other handling occurring before the assembly is mounted in the desired place.

The general object is to provide a magnetic assembly of the above character, in which the backing plate is constructed in a novel manner so as to be simple in construction, easily assembled and effective in holding the parts in place during shipping and other handling.

A more detailed object is to provide a novel snap-type engagement between the plate and the housing so that the plate may merely be pressed into place and then securely holds the magnet and the pole pieces in the housmg.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in which Figure 1 is a plan view of an illustrative embodiment of the present invention associated with a swinging type cabinet door.

Fig. 2 is a plan view of the rear side of a typical magnetic assembly.

Fig. 3 is a fragmentary perspective of the magnetic assembly as applied to the cabinet door shown in Fig. 1.

Fig. 4 is a section taken along the line 4-4 in Fig. 2.

Fig. 5 is a perspective of the backing plate employed in practicing the present invention.

For purposes of illustration, the invention is shown embodied in a magnetic assembly having a housing or casing 11, which assembly serves as a catch on a swinging type cabinet door 12. The housing 11 is secured to the door near the outer edge thereof and on the inside face of the door so that the catch may contact a strike 13 which is fastened to an inside cabinet wall 14. The strike 13 is formed from a magnetic material such as iron or steel so that the magnet assembly 10 will be held against the strike when the door is in the closed position.

As will be seen from Figs. 2 and 4, the housing 11 may be molded from a plastic material and includes a rectangular front wall 15 and side and end walls 16 and 17. The back of the housing is open to provide access to the interior thereof. A permanent magnet bar 18 made of a suitable material such as Alnico, is longitudinally disposed within the housing 11 and is seated in a notch 19 formed in a web 20 which extend across the inside of the housing and are integral therewith. Generally rectangular plates 21 of magnetic material abut against the ends of the magnet 18 and are held there by magnetic attraction thus constituting pole pieces for the magnet. At their forward ends, the corners of the pole pieces 21 are notched to form reduced end portions 22 which project through spaced transverse slots in the front wall 15 of the housing 11. Notching the pole pieces produces shoulders 23 which abut against the inner side of the front wall and limit outward sliding of the pole pieces. The magnet 18 and the pole pieces are held within the housing by a plate 24 which extends across the open back of the housing and is secured to the latter. The backing plate 24 is stamped from a nonmagnetic sheet material such as aluminum.

According to the present invention, the backing plate 24 is secured to the housing 11 by a snap-type connection which permits the plate to be simply pressed into place and which, at the same time, securely connects the plate to the housing to prevent the magnet 18 and the pole pieces 21 from falling out during handling. This connection is formed by resilient detents 25 integral with the side edges of the plate and projecting inwardly therefrom to engage lugs 26 on the inner side of the side walls 16. The lugs 26 are disposed near the back of the housing 11 and may, as shown in the drawings, be molded integrally with the side walls.

In the present instance, the detents 25 are formed by inturned ilanges on the sides of the backing plate 24. The flanges are bowed outwardly to press against the side walls 16 as shown in Fig. 4 and the central portions of the flanges are punched out to form openings 27 into which the lugs 26 project. With this arrangement, the magnet 18 and the pole pieces 21 first are inserted in the housing 11 and then the backing plate is placed across the open back of the housing with the outer edges of the flanges 25 resting on the lugs 26. The plate then is pressed inwardly. This causes the flanges to yield and snap over the lugs so that the parts assume the position shown in Fig. 4. In this position, the outer edge portion 28 of each flange is hooked under the adjacent lug and thus prevents removal of the backing plate.

During shipping or other handling, the magnet 18 and the pole pieces 21, being loose in the housing 11, strike the inner side of the backing plate 24. This tends to push the plate out and may release the flanges 25 from the lugs 26 so that in some instances of severe shock, the parts become disassembled. Usually, the magnet and the pole pieces strike the plate near the end thereof, that is, at a point beyond the flanges 25. Herein, advantage is taken of this fact to construct the plate so as to prevent its removal even under the application of shock.

To achieve the foregoing end, the backing plate 24 is weakened transversely between the end of the magnet 18 and the detent 25 so that the end portions 29 of the plate 24 bend out when the plate is struck by the magnet or the pole pieces 21. For this purpose, transverse slots 30 are punched in the plate beyond each end of the flanges 25. When the magnet or the pole piece strike the plate, they normally hit the end portion 29 and this bends the latter outwardly along a line 31 extending through one of the slots 30 in the manner shown in' broken lines in Fig. 5. Such bending has little or no effect on the flanges 25 and `hence does not cause the flanges to become disengaged from the lugs 26.

It will be observed that the backing plate 24 is simple to make, easy to assemble, and securely held in place. The detents 25 prevent the plate from being accidentally removed during most handling. Due to the weakening of the plate by the slots 30, even the shocks applied to the plate by the magnet 18 and the pole pieces 21 do not release the detents.

I claim as my invention:

l. In a magnetic assembly, the combination of, a housing of nonmagnetic material having front and side walls and open at the rear, a permanent magnet bar loosely placed and longitudinally disposed within said housing, pole pieces of magnetic material abutting against the ends of said magnet and projecting outwardly through said front wall, a backing plate extending across the open rear of said housing to hold said magnet and said pole pieces in the housing, detents projecting inwardly from the side edges of said plate intermediate the ends thereof, and lugs rigid with said side walls and engaged' by said. detents to hold said plate in place, said plate having two transverse slots each disposed between said detent and one end of said magnet whereby shock applied by the magnet and the pole pieces tends to bend the end portions about lines through said slots without releasing said detents from said lugs.

2. In a magnetic assembly, the combination of, a housing of non-magnetic material having front and side walls and open at the rear, a permanent magnet bar loosely placed and longitudinally disposed within said housing, pole pieces of magnetic material abutting against the ends of said magnet and projecting outwardly through said front wall, a backing plate extending across the open rear of said housing to hold said magnet and said pole pieces in the housing, detents projecting inwardly from the side edges of said plate intermediate the ends thereof, and lugs rigid with said side walls and engaged by said detents to hold said plate in place, said plate being Weakened to bend along transverse lines disposed between said detents and the ends of said magnet whereby the end portions of the plate may be bent along said lines without disengaging the detents and the lugs'.

3. In a magnetic assembly, the combination of, a housing of nonmagnetic material having front and side walls and open at the rear, said front wall having spaced openings therein, a permanent magnet bar loosely disposed within said housing, pole pieces of magnetic material abut- Cil ting against the ends of said magnet and having portions projecting through said openings, lugs projecting inwardly from said side walls, a backing plate of nonmagnetie material extending across the open rear of said housing to hold said magnet and said pole pieces in the housing, and flanges projecting inwardly from the side edges of said plate and overlying said lugs, said anges being bowed laterally to bear resiliently against said side walls and having openings therein to receive said lugs whereby the flanges yield as the plate is moved into place and the lugs prevent removal of the plate.

4. in a magnetic assembly, the combination of, a housing of nonmagnetic material having front and side walls and open at the rear, said front wall having spaced openings therein, a permanent magnet bar loosely disposed within said housing, pole pieces of magnetic material abutting against the ends of said magnet and having portions projecting through said openings, lugs projecting inwardly from said side walls, a backing plate of nonmagnetic material extending across the open rear of said housing to hold said magnet and said pole-pieces in the housing, and detents extending inwardly from the side edges of said plate and each having a part engaging one of said lugs to prevent removal of the plate but being yieldable to snap over the lug as said plate is moved into place across the rear of said housing.

Phelon Aug. 28, 1951 Schmitt Feb. 1, 1955 

